Young Adults With Cancer More Likely to Have Germline Mutations, Study Finds

Young patients who are diagnosed with early onset cancers are more likely to have germline mutations that put them at a higher risk of secondary primary cancers and other health complications, according to a new study.

The research, which was presented at the American Association for Cancer Research’s Virtual Meeting II, suggests these patients would benefit from germline genetic testing to help quantify their risk of secondary cancers.

A team of investigators, including Zsofia K. Stadler, MD, of Memorial Sloan Kettering (MSK) Cancer Center, in New York, wanted to determine the prevalence of germline mutations in patients aged 18-39, since young adult patients with germline pathogenic variants can reap particular benefits from proactive surveillance.

The investigators examined the cases of 1201 young adults who were diagnosed with cancer at MSK between the years 2015 and 2019. The team then analyzed the patients’ DNA and blood samples using a next-generation sequencing protocol that included up to 88 genes that have been linked with cancer susceptibility.

Within the 1201 cases, 877 patients were categorized as cases of early onset cancer. Among those, colorectal, breast, kidney, pancreatic, and ovarian cancers were most common cancer types. Another 324 patients were diagnosed with young adult cancers, most commonly sarcoma, and brain, testicular, and thyroid cancers.

When investigators screened these patients for an inherited genetic mutation, they found mutations were present in 1 in 5 (21%) of patients with early onset cancer and in 13% of patients with young-adult cancer.

Patients with early onset cancers were most likely to have mutations in the genes BRCA1, BRCA2, ATM, CHEK2, and the genes associated with Lynch syndrome, Stadler and colleagues found. Patients with young-adult cancers were more likely to have TP53 and SDHA mutations.

Stadler said it is notable that the genetic susceptibility among these patients varies between the groups.

“The distinct set of germline variants appear to suggest that patients with early-onset cancers harbor mutations similar to those also found in older individuals with cancer, but at a higher prevalence,” she said in a statement.

In young adult cancers, however, the mutations tend to be similar to those of pediatric cancer patients, she said.

For clinicians, Stadler said the results of the analysis underscore the need to proactively perform germline genetic testing, since doing so can help identify those patients most at risk for secondary primary cancers.

“Identifying whether a young patient’s cancer occurred in the setting of an inherited cancer predisposition syndrome is important as it can result in substantial change in clinical management, such as increased cancer surveillance aimed at early detection, and risk-reducing surgery to prevent new cancers, and may even have reproductive implications for young families,” she said.

Stadler added that the results of such testing can also have implications for family members of the patients.

The study has some limitations. Among them, it was performed at a single institution and it was limited to solid tumors only, thus it did not include an assessment of young patients with hematological malignancies.

Reference

Stadler ZK, Maio A, Padunan A, et al. Germline mutation prevalence in young adults with cancer. Presented at: American Association for Cancer Research Virtual Annual Meeting II; June 22, 2020.